Electric switch for metering devices



V June 2, 1931. E. H. THOMPSO-N 1,808,387

ELECTRIC SWITCH FOR METERING DEVICES Filed Dec. 3 1923 2 Sheets-Sheet 1June 2, 1931. E THOMPSON I 1,808,387

ELECTRIC SWITCH FOR METERING DEVICES Filed Dec. 3 1928 2 Sheets-Sheet 2ATTORNEY Patented June 2, 1931 UNITED STATES ERNEST H. THOMPSON, OIEVANS'ION, ILLINOIS ELECTRIC SWITCH FOR METERING DEVICES Applicationfiled December'S, 1928. Serial No. 328,541.

This invention relates to an improved type of electrical switch,particularly applicable to the metering device as disclosed inapplicants copending' application filed-March 5,

1928 Serial No. 259,207 and in other improved v meters as covered incertain applications filed concurrently herewith, but it is of course tobe understood that the present invention is not necessarily so limited.

In these metering devices above referred to, a substantially free orfloating piston is adapted to be reciprocated within a cylinder, said Ireciprocation being caused by the flow of the liquid being measured,into and out of the cylinder, theliquid acting directly on the piston.The admissionand discharge of the liquid into and out of the cylinder,is controlled by a suitable valve mechanism and said valve mechanism isin turn controlled by the movements of the'piston, through electricalcontacts or switch devices mounted in each end of the cylinder inposition to be engaged by the piston when in its two extreme positions.

This is all shown in applicantsprior ap plication above referred to, butin said prior construction the electrical switch device has not provensatisfactory for several reasons. The switch assembly as shown in Figs.4 and 19 of said application comprise too many small parts for quickassembly and quantity production. and the-means for mounting this switchmechanism in the end of the cylinder- 'has also proven unsatisfactoryunder working conditions for the reason that it was necessary to usepacking and'this packing would not maintain a fluid tight joint undercontinuous service. i

-The switch mechanism as illustrated in Fig. 23 0f the drawings of saidapplication produces a much better seal or fluid tight joint and saidswitch isvery simple, but being of the dished diaphragm type andnecessarily made of very thin flexible metal, the pressure of the liquidin the cylinder would some times operate'this switch prematurely.

The object of the present invention is to.

produce a switch mechanism 0 the flexible diaphragm type, of very simpleconstruction,

absolutely fluid tight with respect to its mounting in the cylinder andso designed as to eliminate any possibility of premature operation or infact any operation other than that caused by a positive or mechanicalcontact therewith.

Generally stated the improved switch mechanism, which has been devisedparticularly for use in connection with the type of fluid meterhereinbefore referred to, comprises in part a flexible diaphragm sealingthe end of the cylinder, preferably of phosphor-bronze, and thisdiaphragm may or may notbe slightly dished as it has been found that thesame works equally well whether flat or concave. It is of course to beunderstood that the actual head of the cylinder is disposed outside ofthe flexible disk or dia-' phragm and preferably made of relativelyheavy insulating material.

Secured to the outside of the diaphragm 7 is a relatively rigid arm ofthermo metal extending radially thereof, the inner end of the arm beingsecured to the middle portion of the diaphragm. Similarly secured to theinner side of the diaphragm is another arm of thermo metal slightlycurved away from the diaphragm at its outer end, the inner end of thislatter arm being not only secured to the center of the diaphragm, butalso to the inner end of the first mentioned arm.

With this construction it will be apparent that any pressure exerted onthe upper end of the inner arm towards the diaphragm will result in anoutward movement of the outer "end of the outer arm through the flexingof the diaphragm and force said outer end of the outer arm against acontact member suitably positioned and secured in the insulated head ofthe cylinder above referred to.

It isto be also understood that the curved inner arm is in position tobe engaged by the piston as it reciprocates within the cylinder, and theelectrical contact is made each time the piston strikes this. curved armin its to and fro reciprocating movement.

Theimportant feature of this particular construction is that should thediaphragm be forced outwardly by fluid pressure, the outer contact endof the outer arm will be pulled away from the contact "member carried by100 the insulated head, rather than forced into engagement therewith, asin the former construction hereinbefore referred to, all of which willbe further elaborated upon in the detailed description of the device tofollow.

operative position, in connection with applicants fluid meter;

Fig. 2 is an end elevational view;

Fig. 3 is an enlarged view showing the details of the switch per se andE Figs. 4, 5, 6 and 7 are modifications.

Referring to the drawings in detail, the movable contact portion of theimproved switch is mounted in an end section 1 of the meter orsimilardevice 2, concentric with a cylinder 3 in position to be engaged by apiston 4, and secured to the outer face of the end section 1 is asubstantially thick rigid plate 5 of insulating material, saidinsulating plate carrying the stationary contact and having a wireconnection to an electromagnet controlling a valve mechanism of themeter device, said electromagnet and valve mechanism forming no part ofthe present invention and therefore requiring no further description inthe instant application.

The improved switch comprises a circular diaphragm or disk 6 ofrelatively thin phosphor-bronze, preferably slightly dished,hermetically sealed by solder or the-like in a circular opening formedinthe end section 1. Secured to the centerof the disk 6, by a pin I orrivet 7, is a substantially rigid arm 8, preferabl of thermo metal, thefree end of said arm eing provided with a raised contact portion 9adapted to periodically engage a stationary contact 10 mounted in theinsulating plate 5.

The pin or rivet 7 extends through the diaphragm (y and also acts as ameans for secur- ,ing to the inner face of the diaphragm or I 1y securedto the non-flexible arm 8,.this will disk 6, aisubstantially rigid arm11, also preferably formed of thermo metal. The free end of this arm 11is slightly curved away from the diaphragm as at 12 in position to beperiodically engaged by the piston -4 during the operation of the meteror the like.

When the'piston 4 engages the projecting free end 12 of the" arm 11forcin the same inwardly, said arm being non-flexi le and rigidcauseanoutward movement of the free end of said arm 8 into engagement with thestationary contact 10, said movements being permitted by the flexing of.the diaphragm 6, the

diaphragm in returning to its normal position when the pressure isrelieved from the arm 11, automatically disengaging the contacts 9 and10. It will therefore be apparent that said switch cannot be prematurelyoperated by a fluid pressure within the cylinder, 'as'the operation ofthe switch requires a positive engagement of the arm 11 by the piston 4.

It is to be understood that the term thermo metal as used in theforegoing specification in speaking of'the arms 8 and 11 of the switchmechanism, implies a bimetallicconstruction generally known and used inthermostats of the bar type, the said bar comprising two superimposedmetals one having a different 'coeflicient of expansion than the other.This principle is well known and it is thought unnecessary to go intoany further detail description thereof. i

To more clearly show this construction as applied to the particularswitch mechanism herein disclosed, attention is directed to Figure 4 ofthe drawings in which it will be noted that the arms 8 and 11 areillustrated in a an accurate operation thereof under all varying heatconditions. It will be noted that in using this switch mechanism in themeter-mg device as contemplated, the gasoline in expanding upon becomingheated during changed weather conditions, will expand and increase thevolume within the cylinder 3 without increasing in liquid quantity.Under these conditions the piston 4 would arrive at its extremepositions at the opposite ends of the cylinder 3 before the cylinder wasactually full of gasoline as to quantity. Of course, the differencewould be very slight and hardly noticeable upon each reciprocation ofthe piston 4 but upon the continuous use of the apparatus under theseconditions over periods of several hours, the slight difference would besufficient to cause an inaccurate recording of the meter as to thequantity of gasoline passing therethrough.

The present type of switch as shownmore clearly in Fig. 4 has beendesigned to counteract or offset this condition and in forming thebimetallic arm 11, the set curve of said arm is so formed with respectto the characteristics of the two metals of which the arm isconstructed, that said arm will have a tendency to straighten out to asuflicient' degree under increased heat conditions and thereby cause thepiston 4 to travel a slightly increased distance before contacting withthe lower end of the arm 11 which obviously will cause a correspondingdelay in operating the switch to reverse the movements of the piston,and in this way the variations produced in the curved arm 11 by thechange in temperature conditions, will compensate for the slightincrease in volume of the gasoline or a similar fluid flowing throughthe meter to be measured.

i to.

In addition the arm 8 is so construcied that i it will have a tendencyto curve under heat conditions and thereby withdraw the mov- By thiscurving and straightening of the arms 8 and 11 of the switch mechanismunder changes of temperature conditions, said switch mechanism willautomatically compensate for the expansion and contraction-of the gas inthe measuring cylinder 3, and by this compensation will insure anaccurate recording of the liquid quantity of gasoline; passing throughthe metering device as a whole.

Figure-4 also illustrates at 9' a slightly different form of contactmember carried by the movable contact 8 whereby a point contact isproduced in conjunction with the stationary contact/10'. in Figs. 1 and3 this contact portion is formed with a flattened face and is not aseflicient and accurate. as the pointcontact above referred This pointcontact may be constructed as shown in the various modifications illus-'trated in Figs. 5, 6 and 7.

To prevent any possibility of arcing at the switch points, these switchpoints may be submerged in oil as shown at 13 in Fig.

4 in which event the insulating plate 5 is provided with a packing orthe like 14. Likewise there is also a packing 15 used in conjunctionwith the mounting of the sta- I tionary contact 10' all .ofwhich isclearly shown in Fig. 4.

Aside from the operative advantageous features, the complete switch issimple in construction, forms an ellicient seal for the end of the.cylinder and said' switch parts can be prearranged in such a manner asto admirably adapt the same to quantity pro- 'duction and ease and.simplicity in assembling. Furthermore the switch after being assembledand secured in operative position, is capable of continuous and accurateservice for an indefinite period without any attention whatsoever.

Obviously the present invention is capable of many minor changes andapplicant is not to be limited to the specific construction asillustrated and described in theinstant application.

What I claim is:

1. In an electrical switch, the combination with a stationary contact,of a movable contact, a member for moving said movable contact intoengagement with the stationary contact, and a common mounting for saidmovable contact and member, the free ends of said movable contact andmember respec- In the form illustrated.

tively, being eccentrically disposed with respect to said mounting.

2. In an electrical switch, the combination with a stationary con-tact,of a movable contact, a member for moving said movable contact intoengagement with the stationary contact, and a common flexible mountingfor said movable-contact and member, the

free ends of said movable contact and member respectively,beingeccentrically disposed with respect to said mounting.

3. In an electrical switch, the combination with a stationary contact,of a movable contact, a member for moving said movable contact intoengagement with the stationary contact and a common flexible diaphragmmounting for said movable contact and member, the free ends of saidmovable contact and member respectively, being eccentrically disposedwith respect to said mounting.

4. In an electrical switch, the combination with a'stationary contact,of a movable contact, a member for moving said movable contact intoengagement with the stationary contact, and means for positivelysecuring one end of each, the movable contact and member, to each otherand said mounting, the free ends of said movable contact and memberrespectively, being 'eccentrically disposed with respect to saidmounting.

5. In an electrical switch, the combination with astationary contact, ofa movable contact, a member for moving said movable contact intoengagement with the stationary contact, and a common means forpositively securing one end of each, the movable contact and member, toeach other and said mounting, the free ends of said movable contact andmember respectively, being eccentrically disposed with'respect to saidmounting.

6. In an electrical switch, the combination with a stationary contact,of a movable contact, a member for moving said movable contact intoengagement with the stationary contact, and a common flexible mountingfor said movable contact and member, said movable contact and' memberbeing'oppositely disposed each side of the flexible mounting andextending radially from the intermediate portion thereof in onedirection, and means for positively connecting the inner ends of themovable contact and member. to

each other and to the intermediate portion of 7 movable contact andmember, said movable contact and member being oppositely disposed eachside of the flexible mounting and extending radially from the.intermediate portionthereof in one and the same direction, means for:positively connecting the inner ends of the movable contact and memberto each other and to the intermediate portion of said mounting, meansformed on the outer end of the movable contact for engaging thestationary contact and means formed on the outer end of-the aforesaidmember to be engaged by the operating means for the switch.

8. In an electrical switch, the combination with a stationary contact,of a movable contact, an operating member for said movable contact, aflexible diaphragm, said movable contact and operating member eachcomprising substantially rigid arms disposed each side of said diaphragmand radiating from a central portion thereof, and means for positivelysecuring the inner ends of said arms to each other and to the center ofthe diaphragm.

9. In an electrical switch, the combination with a stationary contact,of a movable contact, an operating member for said movable contact, aflexible diaphragm, said movable contact and operating member eachcomprising substantially rigid arms disposed each side of said diaphragmand radiating from a central portion thereof, and means for positivelysecuring the inner ends of said arms to each other and to the center ofthe diaphragm, said operating member being disposed at an angle to theface of said diaphragm.

10. In an electrical switch, the combination with a stationary contact,of a movable contact, an operating member for said movable contact, a.flexible diaphragm, said movable contact and operating member eachcomprising substantially rigid arms disposed each side of said diaphragmand radiating from a central portion thereof, and means for posi tivelysecuring the inner ends of said arms to each other and to the center ofthe diaphragm, said operating member being disposed at an angle to theface of said diaphragm, the parts being so constructed and arrangedwhereby a pressure upon the outer end of the operating member toward thediaphragm will cause a movement of the outer end of the movable contactarm away from said diaphragm through the flexing of the diaphragm.

11. The combination with a cylinder and a piston adapted to bereciprocated therein, of a flexible head comprising a diaphragm for saidcylinder, a substantially rigid arm comprising a, movable contact havingone end secured to the outside intermediate por-- tion ofesaiddiaphragm, a stationary contact, an operating member for said movablecontact secured to the inside intermediate portion of said diaphragmadjacent the point ofattachment of the switch arm thereto, and

- the free end of the operating member being so disposed as to be inposition to be en gaged by said piston, said parts being so constructedand-arranged, whereby such engagebnt will cause an outward movement ofthe free end of the movable contact into engagement with the stationaryv contact. I

12. The combination with a cylinder and a piston adapted to bereciprocated therein, ofa flexible head comprising a diaphragm for saidcylinder, a substantially rigid arm comprising a movable contact havingone end secured to the outside intermediate portion of said diaphragm,an insulating plate providing a substantially rigid head for thecylinder outside of said flexible diaphragm, a stationary contactmounted in said insulating plate, an operating member for said movablecontact secured to the inside intermediate portion of said diaphragmadjacent the point of attachment of the movable contact thereto, and thefree end of the operating member being so disposed as to be in positionto be engaged by said piston, said parts being so constructed andarranged, whereby such engagement will cause an outward movement of thefree end of the movable contact into engagement with the stationarycontact.

13. The combination with a cylinder and a piston adapted to bereciprocated therein,

comprising a flexible head for said cylinder, a substantially rigid armcomprising a movable contact having one end secured to the outsideintermediate portion of said diaphragm, an insulating plate providing asubstantially rigid head for the cylinder outside of said flexiblediaphragm, a stationary contact mounted in said insulating plate, anoperating member for said movable contact secured to the insideintermediate portion of said diaphragm adjacent the point of attachmentof the movable contact thereto, and the free end of the operating memberbeing so disposed as to be in position to be engaged by said piston,said parts being so constructed and arranged, whereby such engagementwill cause an outward movement of the free end of the movable contactinto engagement with the stationary contact 14. The combination with acylinder and and means for'sealingrthe diaphragm in the head of thecylinder, said parts being so constructed and arranged, whereby theaforesaid engagement will cause an outward movement vof the free end ofthe movable contact into engagement with the stationary contact.

15. In an electrical switch, the combination with a stationary contact,of a movable contact member comprising an arm of thermo metal, meanscarried by the free end of the movable contact member for producing apoint contact with said stationary contact member, a curved thermo metalmember for moving said movable contact member into engagement with thestationary contact member and a common flexible mounting for saidmovable contact member and curved member.

16. In an electrical switch, the combination with a stationary contactmember and a mounting therefor, of a movable contact member comprisingan arm of thermo metal, a tapered projection carried by the free end ofsaid movable contact member for producing a point contact with saidstationary contact member, a curved thermo metal member for moving saidmovable contact member into engagement with the stationary contactmember and a common flexible mounting for said movable contact memberand curved member, said stationary and movable contacts being submergedin oil.

In testimony whereof I afiix my signature.

ERNEST H. THOMPSON.

